Machine for coating hollow bodies

ABSTRACT

The invention concerns a machine for simultaneously coating the inner surface of several hollow bodies ( 1 ). In order to increase the performance of said machine, the hollow body bearing plate ( 2 ) has fixing points ( 22 ) disposed next to one another in the form of a matrix and the tube support plate ( 3 ) has vertically disposed gas feed tubes corresponding with said fixing points ( 22 ). A dividing wall ( 15 ) that is also vertically disposed and having correspondingly matching holes placed next to one another in the form of a matrix with a quartz window is fixed on the frame ( 16 ) of the machine. The bearing ( 2 ) and support plates ( 3 ) are provided with a drive mechanism ( 23 ) for horizontal movement into the machine and for loading and unloading said machine. The dividing wall ( 15 ), the hollow body bearing plate ( 2 ), the tube support plate ( 3 ) and the functional accessories ( 10, 11, 23 - 25 ) thereof form a first module. A structure with a second module mirror imaging the first module is fixed on the frame ( 16 ) of the machine. Microwave units ( 12 ) disposed in the form of a matrix are located between said modules.

[0001] The invention concerns a machine for simultaneously coating theinternal surface of a plurality of hollow bodies which are held on asubstantially flat hollow body carrier plate in such a way that arespective gas feed tube for process gas which is secured to asubstantially flat tube support plate can be introduced into the hollowbody and the unit comprising the carrier plate and the support platearranged parallel thereto can be moved into and out of the respectiveevacuatable treatment chamber, wherein the treatment chamber for eachhollow body is equipped with a microwave unit with resonator.

[0002] In order to render plastic hollow bodies, for example PETbottles, impermeable in relation to low-molecular gases such as forexample oxygen, it is known for the PET-bottles to be internallyprovided with a coating, for example an SiO_(x)-layer, because that hasgood barrier properties in relation to low-molecular gases. For thatinternal coating operation, a process gas mixture is blown by way of agas feed tube into the interior of the PET-bottle which was previouslyevacuated, and by means of microwave energy it is possible to fire thatplasma and coat the internal surfaces of the bottle.

[0003] In the laboratory and also already on a larger scale, PET-bottleshave been coated by way of the use of microwave energy. It is alsoalready known for a plurality of hollow bodies to be simultaneouslyinternally coated, using a machine similar to the kind set forth in theopening part of this specification. In the case of that known machine,plastic bottles are fitted with their opening downwardly onto a flathollow body carrier plate in such a way that the respective bottle neckis held by the carrier plate. The carrier plate itself is disposedhorizontally like a tray and a row of bottles extends vertically withtheir bottoms upwardly in such a way that a vertically upstanding gasfeed tube can be introduced from below upwardly through the bottle neckfrom a flat tube support plate which is also arranged horizontally. Thegas feed tubes are also arranged in a row vertically on the horizontaltube support plate, like the row of bottles to be coated. For theoperating procedure the carrier plate has to be moved from a firsthorizontal position into a second horizontal position, in the secondposition the tube support plate is moved vertically into conjunctionwith the carrier plate and the unit consisting of those two plates,after they have been brought together, are further moved in a verticaldirection into an evacuatable treatment chamber and, after thetreatment, moved out of same. Thereafter the carrier plate is also againretracted horizontally and special devices are required to release thecoated bottles from the carrier plate and to strip them therefrom. Byvirtue of the horizontal arrangement of the carrier plate and the tubesupport plate, the amount of space required by such a coating machine islarge. The unloading operation is also complicated and expensive.

[0004] Therefore the object of the invention is to increase the outputof the machine described in the opening part of this specification andnonetheless to permit the machine to be of a more compact overallstructure while requiring a corresponding smaller amount of space. Inthat respect the invention seeks to provide that in particular morehollow bodies per machine unit can be coated in one operating cycle.

[0005] In accordance with the invention that object is attained in that:

[0006] 1. the hollow body carrier plate with fixing places arranged inmutually juxtaposed matrix-like relationship and the tube support platewith gas feed tubes arranged in corresponding relationship withrespective ones of said fixing places are oriented vertically,

[0007] 2. also vertically oriented a separating wall with holes arrangedin correspondingly matching matrix-like mutually juxtaposed relationshipand having quartz windows is fixed to the machine frame,

[0008] 3. the carrier plate and the support plate are provided with adrive for horizontal movement thereof into the machine and out of themachine for loading and unloading,

[0009] 4. the separating wall, the hollow body carrier plate and thetube support plate with their functional accessories form a firstmodule,

[0010] 5. fixed to the machine frame in mirror-image relationship withthe first module is a second module of corresponding structure, and

[0011] 6. the microwave units arranged in matrix-like configuration aredisposed between the modules.

[0012] For the purposes of saving space, machines are frequently builtupwardly. In the case of the coating machine according to the inventionfor example all pumps are fitted vertically at the top onto the machineframe. If the amount of space required horizontally is reduced by virtueof the vertical orientation both of the hollow body carrier plate andalso the tube support plate, the conduits from the pumps to theindividual units can be shorter. The space at the top on the machineframe, which is available due to the reduced horizontal structural areaof the machine, is sufficiently large to mount all vacuum assemblies.The individual spaces and chambers to be supplied however are closertogether, with the consequence of involving the shorter supply lines.

[0013] Both the hollow bodies on the carrier plate and also the gas feedtubes on the tube support plate can be arranged in matrix-likeconfiguration involving one row beside another. Thus a large number ofprocessing places are available in a small space.

[0014] If in addition each module is provided with a stationaryseparating wall which is also arranged vertically for the samespace-saving reasons, in this case also it is possible to provide alarge number of holes with quartz windows, per unit of surface area. Thequartz windows make it possible to separate a for example evacuatablespace on the one hand from another space which is for example underatmospheric pressure, on the other hand. At the same time however thequartz windows are transmissive in regard to the microwave energy. Inthat way lines and antenna can be gas-tightly passed from a supply spaceinto an evacuatable treatment space. Such a separating wall can be of asolid massive structure and can carry comparatively great forces. Theyarise out of the atmospheric pressure on the outside and the vacuum inthe interior of the treatment chamber.

[0015] Spindles, slide rails, roller devices and ball bearing assembliescan be used as the drive for the carrier plate and the support plate.For the purposes of loading and unloading the hollow body carrier plate,the carrier plate has to be withdrawn from the machine so that it iseasily accessible to fitting units having hollow bodies. Preferably itis possible to provide additional drives, or the same drive can be usedto move the carrier plate and the support plate as a unit relative tothe fixed separating wall, and to form a treatment chamber which isgas-tightly closed off. It will be appreciated that such a closedchamber is not to be fitted with hollow bodies. For that purpose, itfirst has to be opened, in which case the drive for withdrawing theplates in the horizontal direction also has to be switched on.

[0016] If the design configuration is such that, in accordance with theinvention, the separating wall, the hollow body carrier plate and thetube support plate with their functional accessories form a firstmodule, then in accordance with the teaching of the invention it ispossible to secure to the machine frame in mirror-image relationshipwith the first module a second module of corresponding structure, andboth modules can be supplied by as many supply devices as possible,which then only have to be provided singly. In that respect, inaccordance with the invention, the microwave units which are arranged ina matrix configuration are preferably disposed between the modules.

[0017] The functional accessories for constructing the respective moduleinclude fixing elements, supply lines, movable and fixed machineelements and the like. For constructing a coating machine in accordancewith the invention, it is possible for those accessories to be of thesame configuration for each module, and to be installed in the samemanner on each module at a suitable location. That can drasticallyreduce manufacturing and maintenance costs.

[0018] A coating machine can be constructed in a very compact fashion,in a very small space, by virtue of the features according to theinvention. The entire machine requires a small amount of space incomparison with the known machines having the horizontally arrangedhollow body carrier plate which is advanced horizontally into itsworking position and which is retracted again after the processingprocedure has been implemented. Many processing stations can be disposedand arranged matrix-like on a plate, in a comparatively small amount ofvertical space, thus affording a high-output coating machine.

[0019] The capital investment costs also have a major effect in regardto the arrangement and structure of the pumps. In a configuration whichis more easily accessible than in the case of machines covering a largesurface area, the vacuum assemblies can be fitted onto the machine frameand the workload of the pumps can be virtually doubled for it issufficient to have one vacuum unit for two modules, as described above.In that respect, it is not impossible that a relatively large number ofmodules can also be disposed on a machine frame of suitable designconfiguration, for example four or six modules which are arrangedstar-like around the microwave supply.

[0020] The microwave units represent a packet of mutually spacedhousings with adjoining coupling-out elements and waveguides which canbe mounted in a matrix-like fashion in large numbers per unit of surfacearea on a vertical plate. The important aspect is that, with anappropriately close assembly of two modules, the microwave energy from agenerator can be passed selectively into the one module (for exampletowards the left) and thereafter into the other module (for exampletowards the right). Then, only one single respective microwave sourceunit is needed for two corresponding stations (being arrangedsubstantially in mirror-image relationship).

[0021] The vertical orientation of the hollow body carrier plate onwhich the hollow bodies are then arranged in such a way that theirlongitudinal centre line extends substantially horizontally and the tubesupport plate provides that, after the coating operation, after whichthe hollow body carrier plate has been moved into the loading andunloading position, the unloading operation can be easily executed. Itis only necessary to introduce ejectors in order to remove the coatedhollow bodies from the carrier plate, which can then automatically dropinto a collecting container disposed therebeneath.

[0022] It is particularly desirable if instead of only one overall twohollow body carrier plates per module are used. As long as one thereofis disposed in the vacuum chamber, the other can be loaded and unloadedoutside. In the course of movement into (or movement out of) the vacuumchamber the plates are then respectively rotated about their verticalaxis in order to move the hollow bodies into the correct position forthe coating operation.

[0023] It is also particularly advantageous in accordance with theinvention if a common cooling supply is provided for both modules. Forthe purposes of temperature control of the microwave units and inparticular the housings thereof with current supply, they are desirablyto be arranged in a cooling chamber. If now the housings of theindividual units are arranged at spacings from each other in amatrix-like configuration with one row beside another and if ventilationgaps and slots are provided in a sufficient quantity and size, then theentire packet of microwave units can be assembled between two modules inan air-conditioning or climatising chamber which surprisingly representsa common cooling supply. If desired the temperatures can be preciselymeasured and controlled at any point in such a chamber.

[0024] It is similarly advantageous if the modular structure inaccordance with the invention is utilised to provide a common gas supplyfor both modules (possibly for a correspondingly larger number of themodules involved). That supply means the supply of the process gas. Forproduction of the plasma process gas is urged in per se known manner outof feed conduits into the gas feed tube from which the process gas thenpasses into the hollow body to be coated. Both for manufacture and alsofor operation of a coating machine of the kind described herein, it isapparent that the possibility of a common gas supply for all the modulesprovided is of interest from a financial point of view (capitalinvestment costs) and a technical point of view.

[0025] It is also advantageous if a common power supply is provided forboth modules (or for the larger number of modules). The power supply canbe respectively disposed in the centre between each two modules, withthe advantage of shorter line lengths and improved switching options. Itis known that the high voltage change-over switches required for themicrowave sources are complicated and expensive. If they switch overalternately from a few volts to the kilovolt range, flashovers occur,which must be controlled in the course of ongoing operation. The fewersuch electrical devices have to be provided, the better it is for thecoating machine. In accordance with the invention it is desirable herefor the arrangement to be such that for example in the case of two unitsthe microwave units are closest to each other. In the case of thearrangement of two units in mirror-image relationship, which is proposedin accordance with the invention, that is achieved by virtue of thecentral arrangement of the microwave units. That then also has acorrespondingly advantageous effect on the power supply.

[0026] It has also been found in accordance with the invention that itis particularly desirable if for each hollow body the microwaveresonator in question is in the form of a hollow cylinder which is fixedto the separating wall. After the carrier and support plates on the onehand and the separating wall on the other hand have been broughttogether to form a gas-tight treatment chamber and after evacuationthereof the plates can be better supported by way of the hollowcylinders which are of a massive structure and which act as resonators.If the hollow cylinders are of a suitably strong and stable nature it ispossible to use even larger carrier and support plates and separatingwalls without flexing phenomena occurring. That makes it possible toconstruct treatment chambers of different dimensions. The vacuum chamberin question can be of a comparatively light structure. In that respectit is to be borne in mind that, with an air pressure of 1 bar, arelatively large separating wall with for example one hundred processingplaces is subject to a loading which corresponds to the force of aweight of 18 tonnes. Microwave resonators are required in any case. Iftherefore they are formed as sturdy rugged hollow cylinders with a sheetmetal wall thickness of for example 2-8 mm, that arrangement thenprovides for advantageous support on outside plates.

[0027] In accordance with the invention the hollow body carrier platecan also be mounted at a side of a plate turner which is pivotable abouta vertical turning axis and then a second hollow body carrier plate canbe mounted on the other side of the plate turner. The output of themachine is further increased by those measures. More specifically, whena hollow body carrier plate is already in the vacuum chamber the otherhollow body carrier plate is readily accessible outside the machine. Itcan then be comfortably and conveniently loaded and unloaded. So thatthe loading procedure (loading and/or unloading) can always beimplemented from the same side, the carrier plates can be rotated abouta vertical axis by virtue of the fact that they can be mounted to theabove-mentioned plate turner. With same they pivot for example through180°. In that way the hollow bodies are moved into the correct positionfor the coating operation.

[0028] Further advantages, features and possible uses of the presentinvention will be apparent from the description hereinafter of preferredembodiments with reference to the accompanying drawings in which:

[0029]FIG. 1 diagrammatically shows a preferred embodiment of a coatingmachine having two modules which are arranged in mirror-imagerelationship with each other, in a first operating condition prior toloading of the treatment chamber,

[0030]FIG. 2 is a broken-away view showing the upper part of the machinediagrammatically shown in FIG. 1, with the gas feed tubes already beingintroduced into the hollow bodies,

[0031]FIG. 3 is a similar broken-away view to FIG. 2 but in a furtheroperating condition in which the unit consisting of the carrier plateand the support plate is moved into the treatment chamber,

[0032]FIG. 4 is an overall perspective view of a preferred embodiment ofthe coating machine with two modules with hollow body carrier plates,drives and microwave units arranged at the centre,

[0033]FIG. 5 is a perspective rear view of the apparatus of FIG. 4,

[0034]FIG. 6 is an isometric view of the machine frame, partly showingthe mirror-image arrangement of the modules,

[0035]FIG. 7 is a front view of the machine frame when viewing in FIG. 6from left front to right rear, wherein a respective hydraulic unit forclosing the treatment chamber is indicated at the right end of themachine frame and at the opposite left end thereof,

[0036]FIG. 8 is a perspective view of two modules, omitting theconnecting part of the machine frame,

[0037]FIG. 9 is also a perspective view of the right-hand module shownin FIG. 8, with microwave units arranged in front thereof, and

[0038]FIGS. 10a) to 10 e) each diagrammatically show a plan view of theembodiment with a plate turner in different loadings positions.

[0039] The machine diagrammatically illustrated in FIG. 1 serves forsimultaneously coating the internal surface of a plurality of hollowbodies 1 which are shown here in the form of bottles. The machine 1 isshown in plan, for which reason the view is onto the upper narrowlongitudinal edge of a flat hollow body carrier plate 2 which isoriented vertically and which is to be envisaged as being movable in ahorizontal direction towards the right or the left for loading andunloading purposes. Shown on a flat tube support plate 3 which is alsooriented vertically is a row of three horizontally projecting gas feedtubes 4 which are disposed in parallel relationship. They can be movedinto and out of the correspondingly arranged hollow bodies 1 in thedirection of movement 6 (horizontal double-headed arrow) by a levermechanism which is generally denoted by reference numeral 5 and which ismost clearly indicated in the perspective view in FIG. 9.

[0040] The unit 7 which consists of the carrier plate 2 and the tubesupport plate 3 arranged in parallel relationship therewith and whichhas become a unit in FIG. 2 by being moved together is also movable intoand out of the treatment chamber generally identified by referencenumeral 8, in the direction of movement indicated by the arrow 6. Thestructure of the machine illustrated herein is designed in a dualfashion and practically symmetrically with respect to a central plane 9(broken line in FIG. 1) which is to be imagined as extending vertically,in such a way that the same machine elements as described hereinbeforeoccur once again in mirror-image relationship. Therefore, in the lowerhalf of FIG. 1, the elements identified by reference numerals 1-8 arecorrespondingly indicated but with the addition of a prime. Therefore,reference numeral 1′ indicates hollow bodies, reference numeral 4′indicates gas feed tubes, and so forth. For the sake of simplicity, thedescription hereinafter is limited to one half of the machine 1.

[0041] The respective treatment chamber 8, 8′ can be evacuated by way ofconduits generally identified by reference numeral 10 and vacuumassemblies generally identified by reference numeral 11. Setting,monitoring and controlling the respective vacuum by way of valves andthe like are known to the man skilled in the art and are not describedin greater detail herein.

[0042] For each hollow body 1, the treatment chamber 8 is equipped witha microwave unit 12 with a resonator 13. An electrical power supply 14(FIG. 1) is responsible for and feeds the entire packet of microwaveunits 12.

[0043] Also oriented vertically is a separating wall 15 which is fixedto the machine frame 16. This stationary separating wall 15 can beclearly seen for example at the right in FIG. 8. The separating wall 15is provided with holes 17 arranged matrix-like in mutually juxtaposedrelationship, with quartz windows 18. The separating wall 15 serves todefine the treatment chamber 8 (for evacuation purposes) and by way ofits holes 17 which are closed by way of quartz windows 18, it allows themicrowave energy from the unit 12 into the treatment chamber 8 with therespective hollow body 1.

[0044] Finally in FIG. 1 reference numeral 19 shows a gas supply which,by way of tube connections 20 for the feed, supplies the tube supportplate 3 and therewith the number of gas feed tubes 4 fixed thereto, withprocess gas. The process gas is emptied by way of the other tubeconnections 21 for the discharge thereof.

[0045] Operation of the machine, insofar as it can be described withreference to FIGS. 1 to 3, is such that firstly the hollow body carrierplate 2 is moved for example to the left or the right in a horizontaldirection perpendicularly to the direction of movement 6, and thereloaded at a plurality of fixing places 22 for the hollow bodies 1.Drives 23 shows in FIG. 4 then displace the hollow body carrier plate 2in a direction parallel to the plane of the carrier plate 2 so that itthen assumes the position shown in FIGS. 1 and 2. The hollow bodies 1are fixed in a matrix-like configuration in a vertically uprightposition on the carrier plate 2 at the fixing places 22, with one rowbeside another. Then further drives move the tube support plate 3 withthe gas feed tubes 4 in the direction of the double-headed arrow 6 sothat the carrier plate 2 and the support plate 3 move closer towardseach other, as shown in FIG. 2. The gas feed tubes 4 thus project intothe hollow bodies 1, as shown in broken line in FIG. 2. Thereafter, thatunit 7 comprising the carrier plate 2 and the support plate 3 moves intothe stationary treatment chamber 8, thus reaching the condition shown inFIG. 3. The hollow bodies 1 are now supplied with process gas by way ofthe tube connections 20 while the air which was previously therein andthereafter also the process gas are withdrawn by way of the tubeconnection for the discharge 21. In parallel therewith the treatmentchamber 8 is evacuated by means of the vacuum assemblies 11 by way ofthe line 10 in order to produce the required low pressure outside thehollow bodies. The electrical power supply 14 is switched on, themicrowave units 12 with the microwave resonators 13 are switched on, andthe gas mixture in the hollow bodies (with process gas) is put into theplasma state. The coating procedure is implemented in per se knownmanner, by way of plasma formation. Thereafter the unit 7 moves againupwardly in the direction of the arrow 6 horizontally out of thetreatment chamber 8 so that once again the condition shown in FIG. 2 isreached. The tube support plate 3 with the gas feed tubes 4 is thenreleased, to attain the position shown in FIG. 1. Thereafter the hollowbody carrier plate 2 can be moved out horizontally towards the left orthe right perpendicularly to the direction of movement 6, and a joltdevice (not shown) releases the individual hollow bodies 1 from thecarrier plate 2. The hollow bodies 1 drop down into a container whichreceives the coated hollow bodies and feeds them to the fillingoperation and so forth.

[0046] Details of the coating machine are shown more fully in FIGS. 4 to9. Thus, FIGS. 4 and 5 show, of the vacuum assembly generally identifiedby reference numeral 11, the main pump set 24 which is arranged at thecentre and the two process pump sets 25 which are arranged laterallythereof. The treatment chambers 8 which are subjected to the effect ofvacuum by operation of those pumps 24, 25 are shown entirely without ahousing and in an open condition, in order to clearly illustrateindividual machine elements.

[0047] The overall perspective view in FIG. 4 shows from the front thehollow body carrier plates 2 which are extracted horizontally from themachine frame 16 by means of the drives 23 and which each carry 10×10hollow bodies 1 in horizontal orientation. This view also shows one ofthe two hollow body carrier plates 2* which have already been moved intothe machine. Disposed at the centre within the machine frame 16 is thepacket of microwave units 12 which correspond in terms of number andarrangement to the 10×10 hollow bodies in the illustrated matrix. Eachmicrowave unit 12 is indicated in the form of a long parallelepiped ofsquare cross-section. This involves the housings which ensure the powersupply for the magnetron (not shown) and which in operation generateheat, for which reason the individual microwave units 12 are arranged ata spacing from each other, as can be clearly seen.

[0048] The entire machine can be roughly divided into three portions,with the two end portions each forming a so-called module 26. This meansthat a separating wall 15, a hollow body carrier plate 2 and a tubesupport plate 3 are provided at each of the two end positions, and aredisposed in mirror-image relationship with each other. It will beappreciated that the module 26 formed thereby also includes allfunctional accessories of the essential elements described and mentionedhereinbefore, for it will be appreciated that those elements must befixed to the machine frame 16. Parts thereof must be capable of beingmoved and all elements require a supply for their function. That alsoincludes the lever mechanism 5 which makes it possible to open and closethe treatment chamber 8. Disposed in the central third portion are themicrowave units 12 which are arranged in a matrix configuration andwhich are thus disposed in a common air-conditioning or climatisingchamber with a cooling supply (not shown). It can be imagined that thecooling chamber begins in FIG. 9 to the left of the cuboidal machineframe 16 and provides for a flow of cooling fluid around the entirepacket of the microwave units 12.

[0049] Numerous details are omitted from FIGS. 6 and 7 in regard to themirror-image structure of the entire apparatus with the three portions,and for the sake of simplicity practically only the machine frame 16with the two hollow body carrier plates 2 for the hollow bodies 1 isshown therein. The mirror-image structure is immediately apparent. Inaddition, a respective loading unit 21 for the hollow bodies 1 can beseen at each of the two carrier plates 2. The hollow bodies 1 are justbeing loaded into the respective carrier plate 2. FIG. 7 shows in a viewwhich is true to scale a front view of the arrangement illustrated inFIG. 6. The two hydraulic rams 28 for the lever mechanisms 5 can be seenat the right-hand and left-hand ends. They provide for opening andclosing the two treatment chambers 8.

[0050]FIG. 8 shows on the left the first module 26 and on the right thesecond module which is also identified by reference numeral 26. Onlyparts of the machine frame 16 (of cuboidal shape) are illustrated inorder to make the Figure clearer. The respective treatment chamber 8 isshown in the opened condition. For that reason the conduits 10 forpumping out and generating the vacuum are also shown in broken-awayform. It is even possible to see two bends 29 which so-to-speak aresuspended in mid-air. It can however be readily imagined that inoperation, upon closure of the treatment chambers 8 those conduits 10will also be moved towards each other and closed. The right-hand half ofFIG. 8 clearly shows the stationary separating wall 15 with the 10×10circular holes 17 arranged in a matrix configuration. Disposed in thoseholes are quartz windows 18 which mechanically separate the microwavecoupling-in effect from the actual evacuatable treatment chamber 8.

[0051] If the right-hand module in FIG. 8 is removed, the hollow bodycarrier plate 2 is moved into the operating condition and the block ofmicrowave units 12 is fitted at the front onto the stationary separatingwall 15, that then gives the perspective view of the right-hand module26 shown in FIG. 9. FIG. 9 more clearly shows the lever mechanism 5 foropening and closing the treatment chamber 8. The hydraulic rams 28 forthe movement drive are omitted here.

[0052]FIG. 10a) shows that operating position in which the hollow bodycarrier plate 2 is moved into the treatment chamber 8 for coating of thehollow bodies 1. A plate turner 30 is arranged outside the treatmentchamber 8 (underneath in FIG. 10 a)), pivotably about a vertical turningaxis 31, and holds the other hollow body carrier plate 2* in thecondition of just being in the process of being loaded with hollowbodies.

[0053]FIG. 10b) shows how the internally coated hollow bodies 1, bymeans of the carrier plate 2, are just beginning to move forwardly outof the treatment chamber 8, as indicated by the downwardly pointingarrow. Thereafter the carrier plate 2 comes to lie against theright-hand side of the plate turner 30 and is latched there.

[0054]FIG. 10c) shows the operating condition in which the plate turner30 is pivoted about its turning axis 31 in the direction of the curvedarrow so that the non-coated hollow bodies move into the position shownin FIG. 10d). In the plan view onto the plate turner 30, the hollow bodycarrier plate 2* is at the right so that it can be released from theplate turner 30 and, in the operating condition shown in FIG. 10e),moved into the treatment chamber 8, in the direction of the upwardlypointing arrow. In the meantime the plate turner 30 remains outside andthe coated hollow bodies 1 can be removed and replaced by uncoatedhollow bodies. After the operation of coating the hollow bodies carriedon the carrier plate 2*, the position shown in FIG. 10a) is thenrestored. The operating procedure is then repeated.

List of References

[0055]  1 hollow body 2, 2′, 2* hollow body carrier plate  3 tubesupport plate  4 gas feed tube  5 lever mechanism  6 direction ofmovement  7 unit comprising 2 and 3  8 treatment chamber  9 notionalvertical plane 10 conduit 11 vacuum assemblies 12 microwave unit 13microwave resonator 14 electrical power supply 15 stationary separatingwall 16 machine frame 17 hole in the separating wall 15 18 quartz window19 gas supply 20 tube connections for the feed 21 tube connections forthe discharge 22 fixing place for hollow bodies 23 drive 24 main pumpset 25 process pump set 26 module 27 loading unit 28 hydraulic ram 29pipe bend 30 plate turner 31 turning axis

1. A machine for simultaneously coating the internal surface of aplurality of hollow bodies (1) which are held on a substantially flathollow body carrier plate (2) in such a way that a respective gas feedtube (4) for process gas which is secured to a substantially flat tubesupport plate (3) can be introduced into the hollow body (1) and theunit (7) comprising the carrier plate (2) and the support plate (3)arranged parallel thereto can be moved into and out of the respectiveevacuatable treatment chamber (8), wherein the treatment chamber (8) foreach hollow body (1) is equipped with a microwave unit (12) withresonator (13), characterised in that
 1. the hollow body carrier plate(2) with fixing places (22) arranged in mutually juxtaposed matrix-likerelationship and the tube support plate (3) with gas feed tubes (4)arranged in corresponding relationship with respective ones of saidfixing places (22) are oriented vertically,
 2. also vertically orienteda separating wall (25) with holes (17) arranged in correspondinglymatching matrix-like mutually juxtaposed relationship and having quartzwindows (18) is fixed to the machine frame (16),
 3. the carrier plate(2) and the support plate (3) are provided with a drive (23) forhorizontal movement thereof into the machine and out of the machine forloading and unloading,
 4. the separating wall (15), the hollow bodycarrier plate (2) and the tube support plate (3) with their functionalaccessories (5, 10, 11, 23-25) form a first module (26),
 5. fixed to themachine frame (16) in mirror-image relationship with the first module(26) is a second module (26) of corresponding structure, and
 6. themicrowave units (12) arranged in matrix-like configuration are disposedbetween the modules (26).
 2. A machine according to claim 1characterised in that a common cooling arrangement is provided for bothmodules (26).
 3. A machine according to claim 1 or claim 2 characterisedin that a common gas supply (19) is provided for both modules (26).
 4. Amachine according to one of claims 1 to 3 characterised in that a commonpower supply (14) is provided for both modules (26).
 5. A machineaccording to one of claims 1 to 4 characterised in that for each hollowbody (1) the microwave resonator (13) in question is in the form of ahollow cylinder fixed to the separating wall (15).
 6. A machineaccording to one of claims 1 to 5 characterised in that the hollow bodycarrier plate (2) can be mounted to one side of a plate turner (30)which is pivotable about a vertical turning axis (31) and that a secondhollow body carrier plate (2*) can be mounted on the other side of theplate turner (30).